Eye Color Guide - The Most Common Eye Colors Swimming Goggles Eye Color Guide - The Most Common Eye Colors The human eye is both beautiful and unique. Much like a fingerprint, each individual's eye color is specific only to them, with no others sharing the same shape, color and appearance. So what eye colors are the most common, and which are the rarest? What is the most common eye color? Which eye color is the rarest? Brown Eyes Brown eyes are the most common eye color in the world with over 55% of the world's population having brown eyes. Brown eye color is a dominant genetic trait, and is created by the presence of melanin in the eye. Over fifty percent of the world's population has brown eyes, with nearly all individuals from Africa and Asia sharing brown eye color. Brown eyes are typically darker than other eye colors, and they may even appear black in certain individuals. Hazel Eyes Hazel eyes are similar to brown eyes, although they are typically lighter in color, and have more of a green-yellow tint. Hazel eyes have a higher concentration of melanin (pigment) around the eye's border, which can result in a multi-colored appearance that varies between copper and green depending on the lighting.

Most people estimate that around 5-8% of the world's population has hazel colored eyes. Blue Eyes Blue eyes are genetically recessive, and therefore much less common worldwide. Blue eyes are formed by the absence of pigments in the eye, where the blue color is formed by the scattering of light as it's reflected off the iris. While blue eyes are less common than brown eyes, they are frequently found from nationalities located near the Baltic sea in northern Europe. It's estimated that approximately 8% of the world's population has blue eyes. Green Eyes Green eye color is often confused with hazel eye color, yet is entirely separate and distinct. Green eye color is the rarest color found around the world, and it is estimated that only around 2% of the world's population has green colored eyes. Green eye color is a result of a mild amount of pigmentation in the eye with a golden tint. When combined with the natural blue scattering of the eye, the colors mix to give a green appearance. Green eye color is most common in northern and central Europe, but can also be found in western Asian cultures on rare occasion.

Silver Eyes Silver eye color is also quite rare, although many consider silver eyes to be a variation of blue eye color. Like blue eyes, silver eyes are the result of a very low amount of pigmentation in the eye, which reflects a gray-silver appearance. Silver eye color is most common in eastern European countries, and is one of the rarer eye colors worldwide. Amber Eyes Amber eyes show off a yellow-copper tone, which results from the yellow colored pigment lipochrome. Amber eyes are very rare worldwide, and are most common in Asia and South American countries. Amber eye color can range from golden yellow to a more copper tone. Overall... if there is one thing we can agree on, it's that all eyes are unique and beautiful. Additionally, thanks to colored contact lenses , it's possible to change your eye color even if you were born with a common brown. Also, make sure to check out our Freshlook Contact Lenses , which are the most popular, and most widely recommended colored contact lens available.

Types of Eye Colors - Most Common & the Rarest Eye Color Search Eye Colors One of the first things that we notice when we see a person are his/her eyes and infact, eyes are amongst the primary features that attract us towards an individual. Even in case of eyes, the aspect that first comes into notice is the eye color. Eye color is basically a polygenic trait of an individual. It is determined by the amount and type of pigments present in the iris of the eyes. In this context, three elements are mainly considered, namely the melanin content of the iris pigment epithelium, the melanin content within the iris stroma and the cellular density of the iris stroma. The main reason for difference in the eye colors of individuals is the melanin content within the iris stroma. Read on to know more about various eye colors. Types of Eye Colors Given below is information on the most common as well as the most rare eye colors in human beings. Brown The eye color that can be described as the most common amongst human beings is brown, with the exception of countries around the Baltic Sea. It is the result of the presence of large amounts of melanin (eumelanin) within the iris stroma.

People who have very dark brown irises might give the appearance of having black eyes. Hazel Another common eye color is hazel. Hazel eyes are the result of a combination of a Rayleigh scattering and a modest amount of melanin in the front border layer of the iris. Hazel eye color has also been defined as the medium-color between light brown and dark green. Hazel is common amongst people in America and Europe, while rare in African, Middle Eastern and Asian people. Gray Gray eye color is considered to be a darker shade of blue (like blue-green). This eye color is related to low melanin in the iris and is related to scant pigmentation throughout the body (like pale skin, light hair, etc). Gray eyes have been found to reveal small amounts of yellow and brown color in the iris. European people, belonging to countries like Russia, Finland and the Baltic States, often have gray eyes, while those in Southeast Asia rarely have this eye color. Gray eyes might seem to change between the shades of blue, green and gray, mainly because of the lighting changes. Blue Blue eyes are quite common amongst people, especially those born in Germany, Netherlands, Iceland, Austria, Sweden, Norway, Denmark, Finland, and Estonia.

The reason behind this eye color is low amounts of melanin within the iris stroma. In Central Asia and Middle East, blue eyes are pretty rare. Since the production of melanin generally increases during the first few years of life, the blue eyes of some babies might darken as they get older. Amber Amber eyes can be defined as the ones having a strong yellowish/golden and russet/coppery tint. The reason behind amber eyes is the deposition of ‘lipochrome’, the yellow pigment, in the iris. It is a very rare eye color and also known as ‘wolf eyes’, since amber eye color is very common in wolves. Green Green eye color is amongst the rarest eye color, with only 1-2% of the world's population born with green eyes. The reason for green eye color is the production of moderate amounts of melanin. People born in Northern Europe and Nordic countries (like Iceland, Sweden, Denmark, Finland, Norway, Germany, and Netherlands) usually have green eyes. Violet Violet eyes are mainly seen in albinos. In effect, the eyes of some albinos appear to be violet because of the mixing of red and blue reflections.

Violet eyes are either a form of blue eyes or a mutation. Red Red is probably the rarest eye color amongst the human population of the world. It is mainly seen in case of albinos and is the result of either large quantities of the ‘normally scarce’ red areas in the eyes or a small leakage of blood into the iris. Black Black is amongst the rarest eye colors in the world. Most of the people who appear to have black eyes have, infact, extremely dark brown eyes that seem to be black. How to Cite What Is the Most Common Eye Color? | eHow What Is the Most Common Eye Color? The appearance of color in a person's eye is a function of the pigments included within the iris. Specific colors are determined by the individual's genes, making some eye colors more common than others. Most Common The most common eye color throughout the world is brown. A high amount of melanin, the pigment that also causes darker hair and skin tone, will cause brown eye color. Very dark eyes may appear to be black. Brown eyes are common through all races and in all parts of the world.

Less Common Less common eye colors include blue (found among people of European descent with lower levels of melanin), hazel (a combination of green and brown), gray (a variant of blue mixed with other hues) and green (typically consolidated to people of Nordic origin). The rarest among these colors is green with only one to two percent of all people born with natural green eyes. Most Rare The rarest eye colors include amber, violet and red. Amber is the result of the yellow pigment lipochrome. Violet eyes are believed to be the result of a lack of enough pigment to fill the entire eye, allowing the blood vessels to become visible. Red, likely the rarest of all human eye colors, is the result of albinism, where the eye lacks any pigment. YourEyeColour: Green Eye Colour: a rare human eye colour Light green eyes Green eyes and red hair Scientist suspects there is a relation between red hair and the green eye colour. It looks like there is a high correlation between those two human traits. Having the red hair colour is also very unique (and recessive). Only 1 - 2 % of the entire human population have naturally red hair. Of course, not only red hair coexist with green eyes.

Also blondes and darker hair colours tend to have green eyes (or the other way around). Green eyes and gender Normally, you would expect a 50/50 gender variation between the eye colours (blue, brown), but scientist found a positive correlation between being a woman and having the green eye colour. Why green eyes are more found in women is still unknown and it is not certain a gender differentiation actually exist. The findings could be biased somehow. red hair, green eyes and being male: the odds are very low Hazel eyes are Green eyes? Some people confuse hazel eyes with green eyes. Hazel eyes are also very rare but are different than green eyes. First of all, hazel eyes have more melanin. They look more brownish and are overall a bit darker, sometimes with a golden teint. People with hazel eyes often notice a considerable change in their eye colour, especially when a lot of light reflect on their eyes. Secondly, some green eyes have a lot of yellow pigment in them. Hazel eyes share this yellow pigmentation hence the confusion. Eyes with a Green-Hazel colour Where do green eyes come from? Green eyes can be found anywhere but you will find them most of the time in Europe.

Some people believe green eyes came to existence due to a mixture of blue and brown eyes. This idea became popular because a lot of green eyes can be found in areas where brown and blue eyes came together. When we look at the map, the highest percentage of green eyes can be found in Scotland. Ireland also has (relative) a lot of green eyed inhabitants. Green eyes have lipochrome. This lipochrome (also known as feomelanin) is a yellowish pigment. People with green eyes and especially those with amber coloured eyes have a lot of this yellow lipochrome inside their irises. Those with blue, brown or grey eyes usually don't have any lipochrome. When you have a lot of lipochrome inside your iris, you might have the amber eye colour. When you only have a small portion of this yellow pigment, your eyes might look a bit more green/blue-ish. The combination of the yellow pigment and low amount of melanin gives rise to light green eyes. When you have a moderate amount of melanin but also lipochrome, your eyes probably look darker green. When you only have a low amount of melanin (and no lipochrome), your eyes look blue.

Light Green Eyes: (very) low amount of melanin + moderate amount of lipochrome Blueish Green Eyes: (very) low amount of melanin + low amount of lipochrome Yellowish Green Eyes: (very) low amount of melanin + (very) high amount of lipochrome Dark Green Eyes: moderate amount of melanin + moderate amount of lipochrome Brownish Green Eyes: high amount of melanin + moderate amount of lipochrome Blue Eyes: (very) low amount of melanin (no lipochrome) Brown Eyes: (very) high amount of melanin (no lipochrome) Amber Eyes: (very) low melanin + very high amount of lipochrome Grey Eyes: low amount of melanin (no lipochrome) Heterochromia Iridum Some people have a truly unique thing going on with their eyes: they have more than one colour! When one eye has a different colour than the other; it is called heterochromia iridum. When only a small portion of the iris has a different colour, it is called: partial heterochromia. complete heterochromia: blue and green Human Eye Color Chart, With Fun Facts Human Eye Color Chart Like This Page? Please Share!

Human eye color charts once were used to "predict" eye colors of children. In the most simplified versions of these charts, brown eyes are considered dominant over both blue and green eyes. And green eyes are thought to be dominant over blue eyes . While these concepts generally are true, the genetics of how eye colors are inherited turn out to be far more complicated than once thought. You can't simply determine the eye colors of grandparents and parents, then calculate the odds of what color a baby's eyes will be. In fact, you can belong to a family with many generations of brown-eyed individuals and still end up with green or blue eyes. Contrary to popular belief, it's also possible for two blue-eyed parents to have a brown-eyed child. Eye colors depend on the amount of pigment (melanin) found in the iris and how it is distributed. Light gray-blue eyes contain much less pigment than extremely dark brown eyes. And there are many shades of eye color in between. Some people are even born with eyes of two different colors, a condition known as heterochromia . Recommended For You TheraTears contains nutrients that match your natural tears. Get $2 off! Eye color percentages vary according to which population is studied.

Obviously, the percentage of dark brown eyes found in Asian and African populations will be much higher than in European populations. And some day, blue may be a rare eye color. This is because more people now select mates outside usual cultural and ethic groups. So when a brown-eyed person marries someone with blue eyes, offspring are more likely to inherit the more dominant brown eyes. Example of a Human Eye Color Chart You can view examples of common human eye colors in the following chart, along with some fun facts. Home » Resources » Eye Color Chart References & Notes >> Don't it make my blue eyes brown: heterochromia and other abnormalities of the iris. Eye (The Scientific Journal of the Royal College of Ophthalmologists; London). January 2012. [Page updated December 2015] Like This Page? Please Share! Recommended For You Frost: Why Do Europeans Have So Many Hair and Eye Colors? Why Do Europeans Have So Many Hair and Eye Colors? Université Laval (Canada) and St. Andrews University (Scotland). [This article summarizes Frost (2006) and includes updates in response to criticism.] Most humans have only one hair color and one eye color.

Europeans are a big exception: their hair is black but also brown, flaxen, golden, or red; their eyes are brown but also blue, gray, hazel, or green. This diversity reaches a maximum in an area centered on the East Baltic and covering northern and eastern Europe. If we move outward, to the south and east, we see a rapid return to the human norm: hair becomes uniformly black and eyes uniformly brown. Why this color diversity? And why only in Europe? Some believe it to be a side effect of natural selection for fairer skin to ensure enough vitamin D at northern latitudes. Yet skin color is weakly influenced by the different alleles for hair color or eye color apart from the ones for red hair or blue eyes. Some have no effect at all on skin pigmentation. Others put the cause down to intermixture with Neanderthals. Yet, according to the mtDNA that has been retrieved, no genetic continuity is discernible between late Neanderthals and early modern Europeans. Perhaps there was some gene flow between the two groups, but certainly not enough to account for the large number of Europeans with neither black hair nor brown eyes.

For others still, this color diversity arose through random factors: genetic drift, founder effects, relaxation of natural selection, etc. But these factors could not have produced such a wide variety of hair and eye hues in the 35,000 years that modern humans have inhabited Europe. The hair-color gene (MC1R) has at least 7 alleles that exist only in Europe and the same is probably true for the eye-color gene (OCA2). If we take the hypothesis of a relaxation of selection, nearly a million years would be needed to accumulate this amount of diversity. Moreover, it is odd that the same sort of diversification has evolved at two different genes whose only point in common is to color a facial feature. Thus, some kind of non-random process seems to have targeted hair and eye color per se, that is, as visible characteristics. But how? And why? For some, including the geneticist Luigi L. Cavalli-Sforza, the answer is sexual selection. This mode of selection intensifies when males outnumber females among individuals ready to mate, or vice versa.

The sex in excess supply has to compete for a mate and resorts to the same strategies that advertisers use to grab attention, such as the use of bright or striking colors. Guppy males (Poecilia reticulata) caught on a single morning from a single creek (Brooks 2002). Rare-color advantage has been studied mainly in guppies and fruit flies but also occurs in other animals. In addition, a number of bird species exhibit color polymorphisms for which the mode of selection remains unclear. Whatever the cause, color polymorphisms are relatively uncommon. They are often hindered by two evolutionary constraints: 1) high predation pressure, this being a constraint on color traits in general, and 2) presence of related species within the same geographic range, apparently because too much intraspecific variability makes it harder to recognize one's own species and leads to hybridization. Representative eye colors (Sturm and Frudakis 2004) In other animals, bright colors are usually due to sexual selection. Sometimes the result may be a "color polymorphism" (see box). A potential mate will respond not simply to a bright color but also to a rare one that stands out from the crowd.

By enhancing reproductive success, however, such a color will also become more common and less eye-catching. Sexual attraction will then shift to less common variants, the eventual result being an equilibrium that maximizes color diversity. This sort of rare-color advantage has been reported in humans. An American researcher, Thomas Thelen, prepared three series of slides featuring attractive women: one with 6 brunettes; another with 1 brunette and 5 blondes; and a third with 1 brunette and 11 blondes. Male subjects then had to select the woman in each series they would most prefer to marry. For the same brunette, preference increased significantly from the first to the third series, i.e., in proportion to the rarity of the brunettes. This rare-color preference may account for the wide range of human hair and eye phenotypes we see today. But why is hair and eye color so much more diverse in Europe than elsewhere? Perhaps because sexual selection was much stronger among ancestral Europeans than in other human populations. Sexual selection intensifies when the "Operational Sex Ratio" (OSR) ceases to be balanced, i.e., when too many of one sex are competing for too few of the other.

To understand why this may have happened in ancestral humans, we can examine the demography of present-day hunter-gatherer bands. Such groups usually develop an OSR imbalance for two reasons: 1) hunting distances are longer and have increased the death rates of young men, typically because game animals are more mobile and/or less numerous per unit of land area; and 2) the cost of providing for a second wife is higher and has reduced the incidence of male polygamy (polygyny), typically because women are procuring less food for themselves through food gathering. As a rule, OSRs are less balanced further away from the equator. In the Temperate Zone, and even more so in the Arctic, game animals roam over larger territories and gatherable food is less available in winter. The most extreme OSR imbalance occurs among hunting peoples of the "steppe-tundra," where almost all consumable biomass is in the form of highly mobile and spatially concentrated herbivores such as caribou, reindeer, or muskox. On the one hand, men die younger because they have to cover long distances in search of herds, with no alternate food sources.

On the other, men are less polygynous because they bear almost the full cost of feeding their families in a habitat that offers women little opportunity for food gathering. With fewer men altogether and even fewer polygynous ones, women have to compete for a limited supply of potential husbands. Ecological zones in Europe at the last glacial maximum, ca 18,000 BP. Steppe-tundra is now reduced to fragments along the northern fringes of Eurasia and North America. During the last ice age, however, when modern humans first arrived, the Scandinavian icecap had pushed it farther south onto the plains of Europe. The more intense sunlight, combined with fertile loess soils, created an expanse of steppe-tundra with unusually high bioproductivity, even at the peak of the ice age. Less productive was the Asian steppe-tundra east of the Urals. It was drier, farther north, and largely polar desert, especially at the glacial maximum. Prospects were better for continuous and substantial human settlement on the European portion of this ecological zone. The European steppe-tundra was distinctive in another way. It took in an area that covers almost the same area where hair and eye color is today most diverse.

Could this be an imprint left on the human genetic landscape by sexual selection? Perhaps. But more proof is needed. One tantalizing piece of evidence is the possibility that these new hair and eye colors are mildly sex-linked, as would be expected if women were more strongly selected for such characteristics. According to an unpublished British study, non-black-haired and non-brown-eyed individuals have longer second fingers in relation to their fourth fingers. This indicates that the new hair and eye colors are associated with a higher ratio of estrogen to testosterone before birth. Interestingly, blond hair has arisen independently among some Aborigines of central Australia and is more frequent there in women than in men. The Aborigine example points to another avenue for research: populations outside Europe among whom new hair and eye colors seem to have appeared independently. There are a few such cases: blond hair among central Australian Aborigines, brown hair among the Yukhagir of eastern Siberia, and fair hair among some Inuit bands of the western Canadian Arctic. Is hair color less diverse in such populations than in Europeans because sexual selection has been less intense or has acted over a shorter period of time?

A final avenue for research might be to extract DNA from skeletal remains in order to chart European MC1R and OCA2 variability over the last ice age. If the sexual selection hypothesis is true, MC1R and OCA2 variability should have developed almost entirely during this time window (c. 25,000 - 10,000 BP). References: Abbie, A.A., and W.R. Adey. 1953. Pigmentation in a central Australian tribe with special reference to fair-headedness. American Journal of Physical Anthropology 11:339-359. Brooks, R. 2002. Variation in female mate choice within guppy populations: population divergence, multiple ornaments and the maintenance of polymorphism. Genetica 116:343-358. Duffy, D.L., N.F. Box, W. Chen, J.S. Palmer, G.W. Montgomery, M.R. James, N.K. Hayward, N.G. Martin, and R.A. Sturm. 2004. Interactive effects of MC1R and OCA2 on melanoma risk phenotypes.

Human Molecular Genetics 13:447-461. Frost, P. 2006. European hair and eye color - A case of frequency-dependent sexual selection? Evolution and Human Behavior 27:85-103 Hughes, K.A., L. Du, F.H. Rodd, and D.N. Reznick. 1999. Familiarity leads to female mate preference for novel males in the guppy, Poecilia reticulata. Animal Behaviour 58:907-916. Makova, K, and H. Norton. 2005. Worldwide polymorphism at the MC1R locus and normal pigmentation variation in humans. Peptides 26:1901-1908. Sturm, R.A., and T.N. Frudakis. 2004. Eye colour: portals into pigmentation genes and ancestry. Trends in Genetics 20:327-332. Thelen, T.H. 1983. Minority type human mate preference. Social Biology, 30, 162-180.

Natural Eye Colors - Eye Care Eye Care Natural Eye Colors You may be aware of the well said Yiddish proverb that says “The eyes are the mirror of the soul”. Just as different skin color shades such as wheat, fair and dark colored, there are even various natural eye colors. There are variations from light to dark shades in the skin and hair due to the extent of melanin pigment present. In a similar way, the pigment defines even the iris color. If there is less amount of melanin, the iris will be lighter with either gray or blue shaded eyes. And if there is high melanin pigment, the iris will be in darker shades like brown or black. The following article gives various natural eye colors, both normal and rare. The variation in the amount of melanin pigment is the only factor for occurrence of so many natural eye colors. Read to know more about the wonderful eye colors. Common Natural Eye Colors Brown: The most common natural eye color observed in human beings is brown. This eye color is observed when there are large amounts of melanin pigment in the iris stroma. Dark brown colored eyes give an appearance of black colored eyes in people.

Blue: This natural eye color is common among people of Finland, Denmark, Sweden, Estonia, Netherlands, Norway, Austria and Germany and very rare among Central Asia and Middle East individuals. Blue eyes are observed as a result of relatively less amount of melanin pigment in the iris stroma than in brown color eyes. Blue eyes darken with age among babies. Gray: This is a darker shade of blue colored eyes. This eye color is observed as a result of less amount of melanin pigment in the iris. Gray eye shade in some people is observed with brown and yellow colors in the eye. People of Finland, Baltic states and Russia usually have gray colored eyes. Hazel: This is also a common eye color and occurs as a combination of slight amount of melanin pigment in the front border of iris and Rayleigh scattering. It is considered to be the merger of both dark green and light brown colors. Rare Natural Eye Colors Violet: Violet or purple colored eyes are generally observed in albinos. A combination of blue and red reflections give the eye a color of violet. This eye color occurs as a result of mutation and is a form of blue eyes. Red: This is the most rarest eye color among human beings.

This eye color is only seen in albinos. Green: Very less percentage of individuals are born with green colored eyes and therefore considered to be a rare eye color. This is observed due to moderate melanin pigment production. Amber: Amber eye color occurs as a result of lipochrome deposition in the iris. This is a yellow pigment that gives a strong golden and coppery tint for the eyes. This is very rare eye color in human beings and usually called wolf eyes as it is common among wolves. Black: This is also a very rare eye color observed in individuals with high amounts of melanin pigment in the iris. The actual fact is the dark brown eye colored people give the appearance of black eye color. The above given are the common and rare natural eye colors. Most of the people have two different eye colors. For instance, one eye color will be light green and the other eye brown colored. This condition of eye is called heterochromia and occur as a result of birth defects. The eye condition can be corrected by intra-ocular implant that improves the eye color appearance. Eye Color - How It Develops | Why Does It Change? - AllAboutVision.com By Burt Dubow, OD Like This Page? Please Share!

See also: Eye color chart • What causes hazel eyes • All about blue eyes • Is green the most attractive eye color? • Which color contact lenses you should choose Eye color often is the genetic trait that fascinates parents the most as a child develops. Will the child's eyes be black, brown, blue, gray, green, hazel or some combination of colors? How a child looks depends on the genetic material each parent contributes to the child. But the parents' genes can mix and match in many different ways. The influences from each parent aren't known until  surprise  after the child is born! How Eye Color Develops The colored part of the eye is called the iris , which has pigmentation that determines our eye color. Her eyes may be blue only temporarily; babies' eyes can change color if the brown pigment melanin develops as they grow. Human eye color originates with three genes, two of which are well understood. These genes account for the most common colors  green, brown, and blue. Other colors, such as gray, hazel and multiple combinations are not fully understood or explainable at this time.

We used to think of brown being "dominant" and blue being "recessive." But modern science has shown that eye color is not at all that simple. Also, eye colors don't come out as a blend of the parents' colors, as in mixing paint. Each parent has two pairs of genes on each chromosome . So multiple possibilities exist, depending on how the "Wheel of Fortune" spins. Dutch researchers have announced they are working on ways to determine eye color of adults with sophisticated DNA analysis that can predict with 90 percent accuracy whether people have brown or blue eyes . In May 2010, the same researchers said they were closing in on the ability to more accurately predict even variable eye colors via DNA analysis and new understanding of how genetics govern eye color. Eye Color Poll Results After collecting 66,493 responses to our eye color poll , we thought it was time to share the results with you: Green was the winner among our site visitors, but responses were spread pretty well over most of the other shades, too. Sidebar continued >> To some, eye color isn't that significant. As someone said on our Facebook page, "All eye colors can be 'the most attractive.' ...

Your eye color has to be about you and express the truth of you to others." Another person posted this comment about eye health being much more important: "The most attractive color is the white of the eye when it is clear and bright, which makes any iris beautiful."  L.S. Researchers said these discoveries also have implications for forensic investigations at crime scenes where recovered DNA may give clues about the actual appearance of suspects. Most babies are born with blue eyes that can darken in their first three years. Darkening occurs if melanin , a brown pigment usually not present at birth, develops with age. Children can have completely different eye colors than either of their parents. But if both parents have brown eyes, it's most likely that their children also will have brown eyes. The darker colors tend to dominate, so brown tends to win out over green, and green tends to win out over blue. However, a brown/blue parent mix doesn't automatically produce a brown-eyed child. Recommended For You Some children are born with irises that don't match in color. Usually this is caused by faulty developmental pigment transport, local trauma either in the womb or shortly after birth or a benign genetic disorder.

Other causes can be inflammation, freckle (diffuse nevus) of the iris and Horner's syndrome . Having an early eye exam is important to make sure nothing serious is going on  and "nothing serious" is the most common finding. Changes In Eye Color The iris is a muscle that expands and contracts to control pupil size. The pupil enlarges in dimmer lighting and grows smaller in brighter lighting. The pupil also shrinks when you focus on near objects, such as a book you are reading. When the pupil size changes, the pigments in the iris compress or spread apart, changing the eye color a bit. Certain emotions can change both the pupil size and the iris color. That's why some people say their eyes change colors when they're angry or loving. What is more important than your vision? Find local eye doctor to get an eye exam Eye color also can change with age. This happens in 10 to 15 percent of the Caucasian population (people who generally have lighter eye colors). For instance, my once very brown eyes are now hazel, a combination of brown and green. However, some hazel eyes actually get darker with age.

Note that if your adult eye color changes pretty dramatically, or if one eye changes from brown to green or blue to brown (called heterochromia ), it's important to see your eye doctor . Eye color changes can be a warning sign of certain diseases, such as Fuch's heterochromic iridocyclitis, Horner's syndrome or pigmentary glaucoma . Ultimately, if you don't like the eye color you inherited, you can always change it with colored contact lenses . But remember, even colored contact lenses are a prescription medical device and must be prescribed and monitored by an eye doctor. Don't buy them over the Internet or get them from a friend without having an eye doctor's prescription! Genes and Eye Color What Color Will Your Baby's Eyes Be? How eye color is inherited is far more complicated than what was thought back in the days when simple charts were created that supposedly could predict the eye color of children based on the eye color of their parents. Generally, though, it's far more likely for two brown-eyed parents to have a blue-eyed child than for two blue-eyed parents to have a brown-eyed child.

This is because the generally less dominant blue-eyed trait can be passed along by brown-eyed people until the genes for the lighter eye color happen to match up, possibly many generations later. Two blue-eyed parents, on the other hand, are much less likely to have darker-eyed children. This is because darker eyes generally are so much more dominant that the genetic trait, when present, ordinarily would first show up in the parent, who then wouldn't be blue-eyed at all. Still, due to the complexities of how genetic traits are passed along, it is entirely possible for two blue-eyed parents to have a brown-eyed child. [Page updated December 23, 2016] Like This Page? Please Share! Recommended For You Facts About Color Blindness | National Eye Institute Facts About Color Blindness What is color blindness? Most of us share a common color vision sensory experience. Some people, however, have a color vision deficiency, which means their perception of colors is different from what most of us see. The most severe forms of these deficiencies are referred to as color blindness. People with color blindness aren’t aware of differences among colors that are obvious to the rest of us.

People who don’t have the more severe types of color blindness may not even be aware of their condition unless they’re tested in a clinic or laboratory. Inherited color blindness is caused by abnormal photopigments. These color-detecting molecules are located in cone-shaped cells within the retina, called cone cells. In humans, several genes are needed for the body to make photopigments, and defects in these genes can lead to color blindness. There are three main kinds of color blindness, based on photopigment defects in the three different kinds of cones that respond to blue, green, and red light. Red-green color blindness is the most common, followed by blue-yellow color blindness. A complete absence of color vision —total color blindness – is rare. Sometimes color blindness can be caused by physical or chemical damage to the eye, the optic nerve, or parts of the brain that process color information. Color vision can also decline with age, most often because of cataract - a clouding and yellowing of the eye’s lens. Who gets color blindness? As many as 8 percent of men and 0.5 percent of women with Northern European ancestry have the common form of red-green color blindness.

Men are much more likely to be colorblind than women because the genes responsible for the most common, inherited color blindness are on the X chromosome. Males only have one X chromosome, while females have two X chromosomes. In females, a functional gene on only one of the X chromosomes is enough to compensate for the loss on the other. This kind of inheritance pattern is called X-linked, and primarily affects males. Inherited color blindness can be present at birth, begin in childhood, or not appear until the adult years. How Genes are Inherited Genes are bundled together on structures called chromosomes. One copy of each chromosome is passed by a parent at conception through egg and sperm cells. The X and Y chromosomes, known as sex chromosomes, determine whether a person is born female (XX) or male (XY) and also carry other traits not related to gender. In X-linked inheritance, the mother carries the mutated gene on one of her X chromosomes and will pass on the mutated gene to 50 percent of her children. Because females have two X chromosomes, the effect of a mutation on one X chromosome is offset by the normal gene on the other X chromosome.

In this case the mother will not have the disease, but she can pass on the mutated gene and so is called a carrier. If a mother is a carrier of an X-linked disease (and the father is not affected), there is a: 1 in 2 chance that a son will have the disease, 1 in 2 chance that a daughter will be a carrier of the disease, No chance that a daughter will have the disease. In autosomal recessive inheritance, it takes two copies of the mutant gene to give rise to the disease. An individual who has one copy of a recessive gene mutation is known as a carrier. When two carriers have a child, there is a: 1 in 4 chance of having a child with the disease, 1 in 2 chance of having a child who is a carrier, 1 in 4 chance of having a child who neither has the disease nor is a carrier. In autosomal dominant inheritance, it takes just one copy of the mutant gene to bring about the disease. When an affected parent with one dominant gene mutation has a child, there is a 1 in 2 chance that a child will inherit the disease. How do we see color?

Normal Human Retina What color is a strawberry? Most of us would say red, but do we all see the same red? Color vision depends on our eyes and brain working together to perceive different properties of light. We see the natural and artificial light that illuminates our world as white, although it is actually a mixture of colors that, perceived on their own, would span the visual spectrum from deep blue to deep red. You can see this when rain separates sunlight into a rainbow or a glass prism separates white light into a multi-color band. The color of light is determined by its wavelength. Longer wavelength corresponds to red light and shorter wavelength corresponds to blue light. Strawberries and other objects reflect some wavelengths of light and absorb others. The reflected light we perceive as color. So, a strawberry is red because its surface is only reflecting the long wavelengths we see as red and absorbing the others. An object appears white when it reflects all wavelengths and black when it absorbs all wavelengths. Vision begins when light enters the eye and the cornea and lens focus it onto the retina, a thin layer of tissue at the back of the eye that contains millions of light-sensitive cells called photoreceptors. Some photoreceptors are shaped like rods and some are shaped like cones.

In each eye there are many more rods than cones – approximately 120 million rods compared to only 6 million cones. Rods and cones both contain photopigment molecules that undergo a chemical change when they absorb light. This chemical change acts like an on-switch, triggering electrical signals that are then passed from the retina to the visual parts of the brain. Rods and cones are different in how they respond to light. Rods are more responsive to dim light, which makes them useful for night vision. Cones are more responsive to bright light, such as in the daytime when light is plentiful. Another important difference is that all rods contain only one photopigment, while cones contain one of three different photopigments. This makes cones sensitive to long (red), medium (green), or short (blue) wavelengths of light. The presence of three types of photopigments, each sensitive to a different part of the visual spectrum, is what gives us our rich color vision. Humans are unusual among mammals for our trichromatic vision – named for the three different types of photopigments we have. Most mammals, including dogs, have just two photopigment types. Other creatures, such as butterflies, have more than three.

They may be able to see colors we can only imagine. Most of us have a full set of the three different cone photopigments and so we share a very similar color vision experience, but because the human eye and brain together translate light into color, each of us sees colors differently. The differences may be slight. Your blue may be more blue than someone else’s, or in the case of color blindness, your red and green may be someone else’s brown. What are the different types of color blindness? The most common types of color blindness are inherited. They are the result of defects in the genes that contain the instructions for making the photopigments found in cones. Some defects alter the photopigment’s sensitivity to color, for example, it might be slightly more sensitive to deeper red and less sensitive to green. Other defects can result in the total loss of a photopigment. Depending on the type of defect and the cone that is affected problems can arise with red, green, or blue color vision. Red-Green Color Blindness The most common types of hereditary color blindness are due to the loss or limited function of red cone (known as protan) or green cone (deutran) photopigments.

This kind of color blindness is commonly referred to as red-green color blindness. Protanomaly: In males with protanomaly, the red cone photopigment is abnormal. Red, orange, and yellow appear greener and colors are not as bright. This condition is mild and doesn’t usually interfere with daily living. Protanomaly is an X-linked disorder estimated to affect 1 percent of males. Protanopia: In males with protanopia, there are no working red cone cells. Red appears as black. Certain shades of orange, yellow, and green all appear as yellow. Protanopia is an X-linked disorder that is estimated to affect 1 percent of males. Deuteranomaly: In males with deuteranomaly, the green cone photopigment is abnormal. Yellow and green appear redder and it is difficult to tell violet from blue. This condition is mild and doesn’t interfere with daily living. Deuteranomaly is the most common form of color blindness and is an X-linked disorder affecting 5 percent of males. Deuteranopia: In males with deuteranopia, there are no working green cone cells. They tend to see reds as brownish-yellow and greens as beige.

Deuteranopia is an X-linked disorder that affects about 1 percent of males. Blue-Yellow Color Blindness Blue-yellow color blindness is rarer than red-green color blindness. Blue-cone (tritan) photopigments are either missing or have limited function. Tritanomaly: People with tritanomaly have functionally limited blue cone cells. Blue appears greener and it can be difficult to tell yellow and red from pink. Tritanomaly is extremely rare. It is an autosomal dominant disorder affecting males and females equally. Tritanopia: People with tritanopia, also known as blue-yellow color blindness, lack blue cone cells. Blue appears green and yellow appears violet or light grey. Tritanopia is an extremely rare autosomal recessive disorder affecting males and females equally. Complete color blindness People with complete color blindness (monochromacy) don’t experience color at all and the clearness of their vision (visual acuity) may also be affected. There are two types of monochromacy: Cone monochromacy: This rare form of color blindness results from a failure of two of the three cone cell photopigments to work.

There is red cone monochromacy, green cone monochromacy, and blue cone monochromacy. People with cone monochromacy have trouble distinguishing colors because the brain needs to compare the signals from different types of cones in order to see color. When only one type of cone works, this comparison isn’t possible. People with blue cone monochromacy, may also have reduced visual acuity, near-sightedness, and uncontrollable eye movements, a condition known as nystagmus. Cone monochromacy is an autosomal recessive disorder. Rod monochromacy or achromatopsia: This type of monochromacy is rare and is the most severe form of color blindness. It is present at birth. None of the cone cells have functional photopigments. Lacking all cone vision, people with rod monochromacy see the world in black, white, and gray. And since rods respond to dim light, people with rod monochromacy tend to be photophobic – very uncomfortable in bright environments. They also experience nystagmus. Rod monochromacy is an autosomal recessive disorder. How is color blindness diagnosed?

Color vision testing Eye care professionals use a variety of tests to diagnose color blindness. These tests can quickly diagnose specific types of color blindness. The Ishihara Color Test is the most common test for red-green color blindness. The test consists of a series of colored circles, called Ishihara plates, each of which contains a collection of dots in different colors and sizes. Within the circle are dots that form a shape clearly visible to those with normal color vision, but invisible or difficult to see for those with red-green color blindness. The newer Cambridge Color Test uses a visual array similar to the Ishihara plates, except displayed on a computer monitor. The goal is to identify a C shape that is different in color from the background. The “C” is presented randomly in one of four orientations. When test-takers see the “C,” they are asked to press one of four keys that correspond to the orientation. The anomaloscope uses a test in which two different light sources have to be matched in color. Looking through the eyepiece, the viewer sees a circle. The upper half is a yellow light that can be adjusted in brightness. The lower half is a combination of red and green lights that can be mixed in variable proportions.

The viewer uses one knob to adjust the brightness of the top half, and another to adjust the color of the lower half. The goal is to make the upper and lower halves the same brightness and color. The HRR Pseudoisochromatic Color Test is another red-green color blindness test that uses color plates to test for color blindness. The Farnsworth-Munsell 100 Hue Test uses a set of blocks or pegs that are roughly the same color but in different hues (shades of the color). The goal is to arrange them in a line in order of hue. This test measures the ability to discriminate subtle color changes. It is used by industries that depend on the accurate color perception of its employees, such as graphic design, photography, and food quality inspection. The Farnsworth Lantern Test is used by the U.S. military to determine the severity of color blindness. Those with mild forms pass the test and are allowed to serve in the armed forces. Are there treatments for color blindness? There is no cure for color blindness. However, people with red-green color blindness may be able to use a special set of lenses to help them perceive colors more accurately. These lenses can only be used outdoors under bright lighting conditions.

Visual aids have also been developed to help people cope with color blindness. There are iPhone and iPad apps, for example, that help people with color blindness discriminate among colors. Some of these apps allow users to snap a photo and tap it anywhere on the image to see the color of that area. More sophisticated apps allow users to find out both color and shades of color. These kinds of apps can be helpful in selecting ripe fruits such as bananas, or finding complementary colors when picking out clothing. How does color blindness affect daily life? Color blindness can make it difficult to read color-coded information such as bar graphs and pie charts. This can be particularly troubling for children who aren’t yet diagnosed with color blindness, since educational materials are often color-coded. Children with red-green color blindness may also have difficulty reading a green chalkboard when yellow chalk is used. Art classes, which require selecting appropriate colors of paint or crayons, may be challenging. Color blindness can go undetected for some time since children will often try to hide their disorder. It’s important to have children tested, particularly boys, if there is a family history of color blindness. Many school systems offer vision screening tests that include color blindness testing.

Once a child is diagnosed, he or she can learn to ask for help with tasks that require color recognition. Simple everyday tasks like cooking meat to the desired color or selecting ripe produce can be a challenge for adults. Children might find food without bright color as less appetizing. Traffic lights pose challenges, since they have to be read by the position of the light. Since most lights are vertical, with green on bottom and red on top, if a light is positioned horizontally, a color blind person has to do a quick mental rotation to read it. Reading maps or buying clothes that match colors can also be difficult. However, these are relatively minor inconveniences and most people with color blindness learn to adapt. What research is being done? NEI-supported researchers have used gene therapy to cure color blindness in adult monkeys. While red-green color blindness affects about 8 percent of Northern European-descended men, it affects all adult male squirrel monkeys because males of the species carry either the gene that makes red photopigment or the gene that makes green photopigment, but never both. The researchers injected the red photopigment gene into the retinas of male monkeys born without it.

The gene was targeted to green cones and allowed those cells to respond to red light. The monkeys were able to see with full three-color (trichromatic) vision. This shows that even though the monkeys’ red cones had been absent from birth, the brain circuitry for detecting red was still in place—offering hope that a similar approach could help people who’ve been colorblind since birth. In another study, NEI-supported researchers were able to restore some color perception in an animal model of rod monochromacy (in which all three cone types are missing), using a gene therapy approach in younger animals. The therapy combined gene delivery with the addition of neurotrophic factors – molecules that are known to help nerve cells grow. Further studies will be testing whether the therapy could be safe and effective in humans. An ongoing NEI clinical trial is testing whether treatment with a growth factor alone could be enough to improve or restore visual function of cone cells in people. This has the potential to help people with color blindness, as well as diseases that are the result of the loss of cones or cone function. Researchers supported by NEI are also studying how cones develop in the retina and how they are maintained and preserved throughout the lifespan.

This research could lead to therapies for color-blindness that occurs during childhood or later in life due to the gradual loss of cones. Last Reviewed:

Question: What is the most common eye color in human beings?
Answer: Brown